When fitting solar panels, I also had a problem as to routing cables through the house, my floors have been repaired by over boarding, so access to void between floor and ceiling would mean removing the ceiling.
So the cables were simply run around the outside of the house.
It will depend on the EV charge point used, what is inside the charge point varies, what I would expect to see is at the origin of your supply, a CT coil around the in coming supply to monitor the total power used in the house, this is connected in some way to the EV charge point, which in turn relays the information to the car so it can adjust the power being taken to ensure you don't exceed the total supplied to the premises.
The method often used is a special cable from the supply point to the EV charge point which includes a data cable. The EV charge point may use a wireless data link, but we are looking at all the other protection also required, like loss of PEN detection, and DC current detection, and the RCD, the installer will select a unit that suits your situation, where I would the supply to the EV charge point is dedicated to that job, so an easy install, but in the main one has to split the supply, the use of henley blocks seems to be favourite, I would expect some thing like this.
This is actually for solar panels, but likely you will end up with some thing similar. There are actually two CT coils, the top one just above the meter works my immersion heater, so it only runs when there is excess solar, there needs to be a gap between the two coils, they can and did interfere with each other.
